1. Field of the Invention
The present invention relates to a leaf spring type coupling and a motor device using the coupling that is capable of shortening the length, in the axial direction, necessary to couple a motor of a coupling with a rotation detector when incorporating the coupling in a motor with a rotation detector.
2. Description of the Related Arts
Conventionally, the structure of a leaf spring type coupling used for a motor with a rotation detector has been as shown in FIG. 4 and FIG. 5.
FIG. 4 is a structural view of a motor with a rotation detector, in which a prior art leaf spring type coupling is incorporated, and FIG. 5 is a perspective view of the assembly of the prior art leaf spring type coupling. Also, components that are the same in the drawings are given the same reference numbers.
In FIG. 4 and FIG. 5, 1 denotes a motor, 2 denotes a motor shaft that protrudes from the non-load side of the motor and acts as the first rotating axis, 3 denotes a rotation detector, 4 denotes a shaft for coupling the motor at the rotation detector side, which protrudes from the rotation detector side and acts as the second rotating axis, 25 denotes a coupling, 26 denotes a flange for mounting the motor shaft that acts as the first shaft connection member, 27 denotes a flange for mounting the rotation detector that acts as the second shaft connection member, 28 denotes an intermediate member, 9 denotes a roughly square-shaped first leaf spring made of a thin flexible member, 10 denotes a roughly square-shaped second leaf spring made of a thin flexible member, and L2 shows the length of a coupling necessary to connect the rotation detector 3 with the motor 1 in its axial direction.
Such a coupling 25 is constructed by connecting the first leaf spring 9 and the second leaf spring 10 to each other by means of bolts 29 and 33 and a nut 35 via the intermediate member 28 between the motor shaft mounting flange 26, in which the motor shaft 2 and the detector side motor coupling shaft 4 are, respectively mounted, and the detector shaft mounting flange 27.
Next, a description is given of the assembling process of the coupling thus constructed, with reference to a disassembled perspective view of the coupling shown in FIG. 6. Also, hole portions 9A and 10A are each provided at the diagonal line positions of a roughly square-shaped hole pattern in the first leaf spring 9 and the second leaf spring 10, respectively, and bolt holes 26A, 27A and 28A that are provided with female threading are provided at both ends in the lengthwise direction of the motor shaft mounting flange 26, detector shaft mounting flange 27, and intermediate member 28.
First, the bolt 31 is caused to pass through the hole portion 10A so that the bolt hole 27A of the detector shaft mounting flange 27 is aligned with the position of the hole portion 10A on the diagonal line of the second leaf spring 10, and the bolt 31 is screwed in the bolt hole 27A, whereby the second leaf spring 10 is connected to the detector shaft mounting flange 27. Next, the bolt 33 is caused to pass through the hole portion 9A so that the bolt hole 26A of the motor shaft mounting flange 26 is aligned with the position of the hole portion 9A on the diagonal line of the first leaf spring 9, and the bolt 33 is screwed in the bolt hole 26A, whereby the first leaf spring 9 is connected to the motor shaft mounting flange 26. Further, the intermediate member 28 is inserted between the leaf spring 10 and the leaf spring 9. And, the bolt 29 is inserted into the hole portion 10A of the second leaf spring 10, the bolt hole 28A of the intermediate member 28, and the hole portion 9A of the first leaf spring 9, so that the bolt hole 28A of the intermediate member 28 is aligned with the hole portions 9A and 10A on the diagonal line of the first and second leaf springs 9 and 10, and simultaneously, the bolt 29 is coupled with the nut 35 from the rear side of the first leaf spring 9, wherein a coupling is completed. Also, the bolts 29, 31 and 33 are, respectively, provided with washers 30, 32 and 34 on both the front surface and rear surface sides of the respective leaf springs 9 and 10.
Next, a description is given of the actions thereof.
As shown in FIG. 4, the coupling 25 thus constructed is attached to the motor shaft 2 of the rotation detector motor and the shaft 4 for coupling the detector side motor, wherein as the motor 1 is caused to rotate, the coupling 25 absorbs eccentricity at high accuracy and couples the rotation detector and the motor to each other by deformation of the two leaf springs 9 and 10 that are coupled between the motor shaft mounting flange 26 and the detector shaft mounting flange 27 via the intermediate member 28.
The prior art leaf spring type coupling is excellent in view of absorbing the eccentricity of the motor shaft 2 and the detector side motor coupling shaft 4 and improving the angular accuracy. However, since all the members of the motor shaft mounting flange 26, first leaf spring 9, intermediate member 28, second leaf spring 10 and detector shaft mounting flange 27 are disposed in a series, the length L2 of the coupling necessary to connect the motor 1 and the rotation detector 3 in the axial direction is made longer, and this causes a problem in view of downsizing the motor with a rotation detector.
Therefore, it is therefore an object to provide a small-sized leaf spring type coupling and a motor device using the coupling that is capable of shortening the length of the coupling in its axial direction.
The present invention provides a leaf spring type coupling including a first shaft connection member for coupling the first rotating axis; a second shaft connection member that is coupled with the second rotating axis and is provided with a protrusion; an intermediate member that intervenes between the above-described first shaft connection member and the above-described second shaft connection member; and a first leaf spring and a second leaf spring, which absorb a deviation in the axial misalignment of the above-described rotating axis and the above-described second rotating axis via the above-described intermediate member and have a roughly square-shaped through-hole; wherein the above-described second shaft connection member causes protrusion of the above-described second shaft connection member to pass through a through-hole of the above-described second leaf spring, and simultaneously, intervenes between the above-described second leaf spring and the above-described intermediate member; the above-described first leaf spring is inserted between the above-described intermediate member and the above-described first shaft connection member; the above-described intermediate member and the above-described second shaft connection member are provided between the above-described first leaf spring and the above-described second leaf spring, and the mounting angle of the above-described intermediate member and the above-described second shaft connection member in the lengthwise direction is aligned with the position on the diagonal line of the peripheral parts of the first and second leaf springs and these are deviated by 90 degrees relatively to each other about their rotating axis.
Further, a part of the above-described second shaft connection member is made tapered so that the above-described second shaft connection member is detachable from the above-described second rotating axis.
Further, the present invention provides a motor device including the above-described leaf spring type coupling and a motor with a rotation detector, in which the coupling is incorporated.